Top 5 spot shuffle?

Are they rotating/cycling?

[mat]

For what seems like weeks now, a particular three-word combo that I use as my benchmark phrase has seen an almost daily shuffle of positions 2, 3 and 4, very occasionally 5.

Top ten sites always the same, just the order changing in the upper half. Seems to be too systematic to be 'flux, just wondered if anyone else seeing this? Lots of people talking about 'randomnisation' of the results, maybe they're experimenting?

[toolkit]

I think they're factoring in LocalRank